1. Field of the Invention
The present invention relates generally to electrically-driven dump trucks and specifically to an electrically-driven dump truck with increased side visibility.
2. Description of the Related Art
A dump truck refers generally to a truck with a mechanical apparatus that is used to unload all the loaded material from its dump box at a time by lifting the front of the dump box. There are two types of dump trucks: on-road and off-road dump trucks. The off-road dump trucks are specifically designed for use at large-scale construction sites or mines. Such off-road dump trucks have been increased in size for the purpose of improving labor efficiency. For instance, giant dump trucks are now widely used at strip mines around the world.
For the purpose of improving the efficiency and maintainability of such giant dump trucks, their drive scheme is now shifting from a diesel-engine direct drive scheme to an electric drive scheme that involves the use of an alternating-current (AC) electric motor powered by a diesel engine. An example of a dump truck employing such an electric drive scheme is disclosed in JP,A 2007-16906 (pp. 6-7, FIGS. 1-2). Such an electrically-driven dump truck operates its electric motor as a generator during braking and causes resistors to consume the regenerative electric power from the electric motor, thereby obtaining a braking force. This braking method is termed dynamic braking (retarder-aided braking).